WO 2007/088353 A1 discloses a tool clamping system which has a cutting body configured as a cutting insert, a clamping screw clamping the cutting insert in the tool seat, and a setting element for the precision setting of the cutting insert. In this case, the setting element is configured as a longitudinally displaceable setting wedge. The setting wedge has an active surface which runs obliquely relative to the basic body and which applies pressure to the cutting-body rear wall of the cutting insert, said cutting-body rear wall being remote from the active cutting edge of the cutting insert. The basic body of the setting element is of cylindrical configuration. The cylindrical configuration of the basic body has the advantage that the basic body of the setting element is automatically oriented in the likewise cylindrical setting element guide in such a way that the active surface of the setting element always bears flush against the rear side, assigned to it, of the cutting insert, the cutting-body rear wall. To realize its adjusting movement, the setting element is mounted in its guide in a longitudinally displaceable manner. To drive the setting element in its guide, a headless screw is screwed in at the end of the guide, said headless screw acting with the end of its shank upon the free end of the setting element, said free end being remote from the active surface of the setting element. The setting element is moved in the longitudinal direction of the guide toward the cutting-body rear wall by screwing the headless screw into the guide. The pressure on the rear wall of the cutting insert is reduced by unscrewing the headless screw, such that the setting element is moved in the guide away from the cutting insert.
A disadvantage with this embodiment is the fact that the setting element, which is actually very small, can undesirably rotate in its guide during the tool change. If this undesirable rotation is exceeded to a certain degree, the aforementioned effect of the automatic orientation of the setting element also no longer functions. On the contrary, the setting element encounters the cutting-body rear wall of the newly clamped cutting insert with regions of its active end which are completely unsuitable for the precision setting of the cutting insert. In the worst case, the basic body of the setting element and/or the indexable cutting insert will even be damaged. However, for the proper functioning of the setting element, it is necessary for the active surface to bear in a flush, that is to say planar, manner against the cutting-body rear wall active as bearing surface. In contrast, if the setting element bears against the cutting insert only in a point-like manner or on one side, this leads to undesirable stresses in the tool or to inaccuracies in the setting.